Article

Correlation Between Incisional Biopsy Histological Subtype and a Mohs Surgery Specimen for Nonmelanoma Skin Cancer

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Abstract

Background: Histological diagnosis of a clinically suspected nonmelanoma skin cancer (NMSC) is recommended before treatment. For NMSC, concordance between the histological subtype of the preoperative biopsy and the excision specimen of basal cell carcinoma (BCC) has been reported to range from 10% to 81%. No large study on the concordance between NMSC histology seen in a preoperative biopsy with the following tumour specimen from Mohs micrographic surgery (MMS) has been performed in a Latin American population. Objective: The aim of this study was to analyse and compare the histological subtype of the incisional biopsies reviewed by the dermatopathologist with the histological subtype of the tumour specimen obtained during MMS interpreted by the dermatopathologist and the Mohs surgeon. Methods: A retrospective analysis of 320 NMSC was performed. The interobserver correlation was based on kappa values. Results: The mean weighted kappa value between the preoperative NMSC biopsy and intraoperative histological subtype of the tumour specimen from MMS analysed by the Mohs surgeon and the dermatopathologist was 0.22 and 0.24, respectively. The correlation in the histologic subtype of the intraoperative tumour specimen from MMS that was interpreted by the dermatopathologist and Mohs surgeon was 0.58. Conclusions: Dermatologists need to be aware of the limited value of incisional biopsies to accurately diagnose the histological subtype of a NMSC. The concordance rate in the histological diagnosis of the tumour specimens that were obtained from MMS between the Mohs surgeon and the dermatopathologist is moderate. However, the correlation is low compared with incisional biopsy subtypes.

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... Assim, as variações amostrais nas biopsias pre-operatorias poderiam levar a uma interpretação diferente do subtipo histologico. 15 Estudos anteriores mostraram uma concordância moderada variando de 51,1% a 82% entre o subtipo CPNM em biópsias incisionais e subsequente excisão cirúrgica. 15,16 Quanto ao tipo histológico dos tumores estudados, os CBCs representaram 67,2% da amostra e os CECs, 7,89%. ...
... 15 Estudos anteriores mostraram uma concordância moderada variando de 51,1% a 82% entre o subtipo CPNM em biópsias incisionais e subsequente excisão cirúrgica. 15,16 Quanto ao tipo histológico dos tumores estudados, os CBCs representaram 67,2% da amostra e os CECs, 7,89%. Dados da literatura 7,10,14 apontam o CBC como o tipo de câncer de pele mais frequente. ...
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Mohs micrographic surgery (MMS) can achieve high cure rates in skin cancer treatment and remove as little healthy tissue as possible. OBJECTIVE: This study aims to characterize patients undergoing Mohs micrographic surgery and to assess predictive factors for a higher number of surgical phases. METHODS: Observational, cross-sectional, retrospective, and descriptive study conducted in a reference service for micrographic surgery from 2013 to 2019. The medical records of 230 patients (256 lesions) were reviewed. RESULTS: Injuries with recurrence had significantly more stages than injuries without recurrence (1.69 stages versus 1.31 stages). Tumors greater than 2 cm had a greater number of phases than those smaller than 1 cm and between 1.1 and 2.2 cm (2.0 versus 1.08 and 1.22, respectively). When comparing the locations of the lesions with the number of phases, there was no significant difference. There was a considerable difference regarding the preoperative histological subtypes: aggressive basal cell carcinomas (BCC) required a higher number of phases than non-aggressive BCCs. CONCLUSIONS: Our study demonstrates, corroborating data from the literature, that the risk factors described are directly related to a greater number of stages of Mohs micrographic surgery.
... This system was initially accepted (median score 4), but the agreement disappeared in the posterior survey (median score: 3) after a discussion with the complete team since diagnostic incertitude due to partial resection or the presence of artifacts is practically inherent in the procedure. [15][16][17] ...
Article
Background Histopathological classification of basal cell carcinoma (BCC) has important prognostic and therapeutic implications, but reproducibility of BCC subtyping among dermatopathologists is poor. Objectives To obtain a consensus paper on BCC classification and subtype definitions. Methods A panel of 12 recognized dermatopathologists (G12) from nine European countries used a modified Delphi method and evaluated 100 BCC cases uploaded to a website. The strategy involved five steps: (I) agreement on definitions for WHO 2018 BCC subtypes; (II) classification of 100 BCCs using the agreed definitions; (III) discussion on the weak points of the WHO classification and proposal of a new classification with clinical insights; (IV) re-evaluation of the 100 BCCs using the new classification; and (V) external independent evaluation by 10 experienced dermatopathologists (G10). Results A simplified classification unifying infiltrating, sclerosing, and micronodular BCCs into a single “infiltrative BCC” subtype improved reproducibility and was practical from a clinical standpoint. Fleiss’ κ values increased for all subtypes, and the level of agreement improved from fair to moderate for the nodular and the unified infiltrative BCC groups, respectively. The agreement for basosquamous cell carcinoma remained fair, but κ values increased from 0.276 to 0.342. The results were similar for the G10 group. Delphi consensus was not achieved for the concept of trichoblastic carcinoma. In histopathological reports of BCC displaying multiple subtypes, only the most aggressive subtype should be mentioned, except superficial BCC involving margins. Conclusions The three BCC subtypes with infiltrative growth pattern, characteristically associated with higher risk of deep involvement (infiltrating, sclerosing, and micronodular), should be unified in a single group. The concise and encompassing term “infiltrative BCCs” can be used for these tumors. A binary classification of BCC into low-risk and high-risk subtypes on histopathological grounds alone is questionable; correlation with clinical factors is necessary to determine BCC risk and therapeutic approach.
... One study found that 21.1% of biopsies under diagnosed the aggressiveness of BCCs and SCCs when compared with subsequent MMS pathology samples, owing to the heterogeneity of many tumors and lack of complete tumor visualization with biopsy ( Izikson et al., 2010 ). Therefore, if the overall pathology or base of the tumor differs from the pathology of the biopsy sample, this may affect risk stratification and reduce treatment success ( Bartoš and Kullová, 2016;Cortés-Peralta et al., 2018;Sexton et al., 1990 ). ...
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Keratinocyte carcinomas (KCs) are now an epidemic in The United States of America, especially in elderly patients. KCs, including basal cell carcinoma and squamous cell carcinoma, can lead to disfigurement and occasionally death. However, the lower mortality rate associated with KC compared with melanoma allows for increased flexibility in the selection of treatment. Flexibility in treatment is particularly important in the elderly given that this patient population often has medical comorbidities that should be considered. These patients may have multiple KCs, higher risk tolerance to recurrence, and different concerns about cosmetic outcomes compared with their younger counterparts. We review treatment options for KCs and how the selection of each option may affect the elderly patient. Keywords: Keratinocyte carcinoma, nonmelanoma skin cancer, basal cell carcinoma, squamous cell carcinoma, elderly
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Background Initial biopsies of cutaneous squamous cell carcinomas (cSCC) may not reveal aggressive histologic features, which would otherwise inform appropriate surgical management and patient education. Objective To assess the incidence of and risk factors for histopathologic upgrading of cSCC during Mohs micrographic surgery (MMS). Methods Retrospective cohort study of invasive cSCCs treated with MMS 2017-2019 at one academic institution. An “upgrade” was defined as a lesser degree of differentiation (poor or moderate) and/or bony or perineural invasion identified during MMS that was not reported in histopathologic evaluation of the initial biopsy. Results 115 out of 1,558 (7.4%) tumors were upgraded during MMS. In multivariate logistic regression analysis, male sex, prior field treatment, location on the ear/lip, rapid growth of cSCC, and tumor diameter ≥ 2 cm were significant predictors of tumor upgrading. Upgraded tumors were more likely to require ≥ 3 MMS stages to clear, complicated closure (flap or graft), or outside (referral) repairs. Limitations Single center study, retrospective, interrater variability Conclusion A significant proportion of cSCCs are histopathologically upgraded with more aggressive features during MMS. Routinely documented patient and tumor characteristics can predict tumor upgrading and assist clinicians in directing management of potentially high-risk cSCC patients.
Article
Background: Few data exist to guide the application of Mohs micrographic surgery (MMS) in the pediatric population. Objective: To summarize the clinical characteristics of children undergoing MMS, identify challenges that limit the use of MMS in this population, and examine how these challenges can be overcome. Methods: A systematic review of PubMed and EMBASE, from inception of databases to November 2nd, 2019, identified all cases of pediatric skin lesions treated with MMS. Results: A total of 111 patients were included. The median patient age was 11 years (range 6 weeks to 17 years). The most commonly treated tumor was DFSP (n=62), followed by BCC (n=30). The most common location was the head and neck (n=34), followed by trunk (n=28) and extremities (n=23).The most commonly cited challenges in the application of MMS in children included: patient cooperation, concerns for safety of prolonged general anesthesia, availability of a Mohs surgery service in the pediatric setting, and access to a histopathology lab experienced in MMS sectioning. Limitations: Many articles did not report specific patient characteristics. Conclusion: Multiple obstacles limit the application of MMS in pediatrics. This review describes practical methods to circumvent these obstacles in order to facilitate the appropriate use of MMS in children.
Article
Background/objectives Therapeutic approaches to keratinocyte carcinoma rely on the accuracy of the biopsy to correctly identify, grade or subtype the tumour. Several studies have investigated the frequency and nature of histopathological discordance between the biopsy and final excision specimen. We analysed information extracted from an Australian Mohs micrographic surgery (MMS) database and compared similar studies. Methods An Australian MMS database was retrospectively reviewed for a period of one year. Correlation was made between the preoperative lesion diagnosis based on the formal pathology report and the histopathological results reported at the time of MMS. A systematic PubMed review of similar articles was also performed. Results A total of 464 cancers (406 BCC and 58 SCC) in 399 patients were included. The overall discrepancy rate in the histopathological classification of keratinocyte carcinoma in our study (42.2%) and the proportion of cases in which the biopsy underestimated the aggressiveness of the tumour (12.9%) were consistent with those found in similar studies. The percentage of biopsies that failed to identify an aggressive BCC subtype (31.6%), and that of biopsy‐proven superficial BCC that demonstrated an invasive component in MMS (79.3%), were higher in our study than in comparable studies. The high prevalence of mixed histopathological subtypes, especially amongst BCC with discordant histopathological results, appeared as an important contributing factor. Conclusions Despite subtle differences, the results from this Australian study support the results from similar studies and highlight that the biopsy report should be carefully interpreted in combination with the clinical findings.
Article
Background Basal cell carcinomas (BCC) with high-risk features are preferably treated by Mohs micrographic surgery (MMS). Studies have shown clinicopathologic characteristics that may predict more stages required for clearance. However, few studies have correlated such factors with the number of millimeters removed per stage. Objective To determine margins necessary for BCC clearance based on tumor features, especially for tumors < 6mm, and to suggest initial margins for MMS and margins for WLE. Methods Retrospective analysis of 295 consecutive MMS. Variables analyzed included patient age, sex, immune status, lesion size, location, histologic subtype, borders, stage number, and millimeters excised per stage. Results BCC < 6 mm had a clearance rate of 96% with 3-mm margins. In adjusted multivariable analysis, superficial, micronodular, infiltrative, and morpheaform subtypes were associated with larger margins; whereas clinically well-defined tumors were associated with smaller margins. Limitations Due to limited sample of certain subtypes, the recommendation of 3-mm margin is better suited for nodular tumors. Conclusion This data helps guide initial MMS and WLE margins required for tumor clearance according to tumor features. Nodular BCC < 6 mm may be cleared with 3-mm margins instead of the current 4-mm margin recommendation.
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Background Diagnosis of clinically suspected basal cell carcinoma (BCC) by histological confirmation with punch biopsy has been recommended before treatment. Even shave biopsy has been proposed as useful to predict the correct subtype in primary BCC in 76–81%, whereas the agreement between histological BCC subtype on punch biopsy and subsequent excision specimens in recurrent BCC is 67.1%. However, no large studies on the agreement between histological BCC subtype seen on punch biopsy and the following surgical excision are performed in primary BCC. Objective The aims of this study were (i) to establish the agreement between histological BCC subtype on punch biopsy and the subsequent surgical excision of primary BCC and; (ii) to investigate the proportion of primary BCCs in which punch biopsy enables identification of the most aggressive growth pattern. Methods Retrospective analyses of 243 primary BCCs with both punch biopsy and subsequent surgical excision. Analyses were based on the most aggressive histological subtype of the tumour. Results The agreement between BCC subtype on punch biopsy and the subsequent surgical excision of primary BCCs was 60.9%. A punch biopsy can predict the most aggressive growth pattern of primary BCCs in 84.4%. Seventy-four percentage of all primary BCCs consisted of more than one histological subtype. Conclusion Dermatologists and other physicians have to be aware of the limited diagnostic value of a punch biopsy to determine the histological BCC subtype of the whole lesion. Misdiagnosis of the subtype will lead to undertreatment in one of six primary BCCs.
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Basal cell carcinoma (BCC) is a common skin cancer for which the treatment and recurrence risk correlate with the histologic subtype. Limited information is available regarding the accuracy of biopsy in diagnosing BCC subtypes. We sought to determine the correlation between BCC subtypes present in a biopsy specimen and the actual subtypes present in a tumor. In this retrospective study, skin biopsy specimens and corresponding excisions were reviewed. All histologic subtypes present in the biopsy specimen were reported and compared with the composite BCC subtype present in the biopsy specimen and excision. A total of 232 biopsy specimens and corresponding wide excisions were examined. The biopsy specimen accuracy rate was 82% for punch and shave biopsy specimens. Mixed histologic subtypes were seen in 54% of the cases, half of which contained an aggressive subtype (infiltrative, morpheaform, or micronodular). There was an 18% discordance rate between the biopsy specimen subtype and the composite subtype. Importantly, 40% of these discordant cases (7% of all cases examined) had an aggressive subtype that was not sampled in the initial biopsy specimen. Furthermore, some cases were misidentified as infiltrative subtype in the biopsy specimen as a result of misinterpretation of surface ulceration and reactive stromal changes. The limited number of punch biopsy specimens and the fact that Mohs excisions were not included are limitations. Punch and shave biopsy specimens provided adequate sampling for correct BCC subtyping in 82% of the cases examined. However, 18% of the biopsy specimens were misidentified, some of which missed an aggressive component. Thus, there are potential pitfalls in the identification of BCC subtypes in biopsy specimens, which may have important implications in treatment outcome.
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This article provides a protocol for the systematic approach to the technique of Mohs micrographic surgery. Each step, from tumor excision and tissue mapping, to specimen processing and histologic interpretation, through wound closure and postoperative management, is covered. The advantages of Mohs surgery over other treatment modalities are observed histologic margin control, superior cure rates, and maximal tissue-sparing potential. The increased preservation of normal tissue leads to smaller surgical defects, optimal reconstructive results, and diminished risk of poor surgical outcomes. Overall, the risks of the procedure are few, the benefits numerous, and the outcomes worth the time and effort spent in learning the technique.
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The type of treatment for a basal cell carcinoma (BCC) depends on the histologic subtype. Histologic examination is usually performed on incisional biopsy specimens. In primary BCC, the histologic subtype is correctly identified with a punch biopsy in 80.7% of cases. In recurrent BCC, correct identification is more difficult because of discontinuous growth caused by scar formation. Because an aggressive histologic subtype has a significantly higher risk for recurrence in these tumors, the histologic subtype is at least as important in recurrent BCC as it is in primary BCC. To investigate the correlation between histologic findings on punch biopsy specimens and subsequent excision specimens in recurrent BCC. Furthermore, we sought to clarify how often an aggressive histologic subtype was missed, based on the punch biopsy specimen. We compared the histologic subtype in a punch biopsy specimen with the subsequent excision specimen in recurrent BCC. All BCCs were coded and judged randomly by the same dermatopathologist. In 24 of 73 investigated BCCs (32.9%), the histologic subtype of the initial biopsy did not match with the histologic subtype of the subsequent excision. Of the 37 excised BCCs with an aggressive histologic subtype, 7 (19%) were missed by the initial punch biopsy. Intraobserver variation may have affected the results of this study. Discriminating tumors with any aggressive growth is relevant for treatment. However, in recurrent BCC, the histology of the biopsy specimen does not always correlate with the histology of the definitive excision. This may have important therapeutic implications.
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The low recurrence rate and tissue-sparing benefit associated with Mohs micrographic surgery (MMS) requires accurate interpretation of frozen sections by the MMS surgeon. We sought to assess concordance between dermatopathologists and MMS surgeons when reporting cutaneous malignancy in the MMS setting. This study is a retrospective analysis of 1156 slides submitted during 10 years as part of a pre-existing randomized, blinded, quality assurance protocol. Slides were read by one of 5 dermatopathologists and represent cases from 3 MMS surgeons and 5 MMS fellows. Agreement or disagreement was recorded. Of the 1156 slides, 32 slides (2.8%) were disparate. Aside from differences regarding intraepidermal neoplasia, the concordance rate was 99.7%. This study represents data collected at a single institution in the United States alone. There was statistically significant concordance between MMS surgeons and dermatopathologists in frozen section interpretation in the MMS setting. Discordance was primarily related to the interpretation of in situ malignancy.